In order to facilitate packaging of mass produced articles, such as frozen goods, into counted groups preparatory to placing the articles into cartons or bags containing a known number of articles, it is known to segregate such articles into a single-file stream to enable accurate counting and grouping. Such counting and grouping can then be performed by traditional means using simple beam interruption counters or the like and simple activated gates or valves. Such apparatus is well known.
Typically, such apparatus may be used with an inspection system, an example of which was disclosed by De La Ballina in United States published patent application No. 2005099620, which uses known techniques with regard to imaging and metrology with cameras, overhead lighting and backlighting. The De La Ballina system has a row of hinged fingers operating selectively in drawbridge fashion. When in a lowered condition, the fingers generally lie in the plane of the conveyor to allow accepted articles to pass from the first conveyor to an out-feed conveyor and, when in a raised condition, allow rejected articles to drop through the resulting gap for disposal. Different sets of the fingers can be raised together to select specific lines of articles for rejection.
Known imaging systems for inspecting articles on a conveyor are not entirely satisfactory where a high proportion of articles are randomly distributed and/or in clusters, i.e., touching, partially overlapping or interlocked together, since it is then difficult to determine whether or not a particular article meets the prescribed criteria for acceptance or rejection. Consequently, De La Ballina's system employs equipment upstream of the imaging system to segregate the articles from each other so that the imaging system can differentiate between them and determine which articles are to be rejected and the particular set of fingers to raise in order to drop only the rejected articles below the conveyor for disposal. A disadvantage of such an arrangement, however, is that the additional upstream equipment increases cost.
A further disadvantage arises when it is required to separate the acceptable articles into groups or batches of a prescribed number for packaging or further processing. Thus, De La Ballina's system or the like would require equipment downstream of the fingers for counting the accepted articles and separating them into groups for packaging. The counting and grouping equipment typically requires singulating the articles so that they follow one another in a single line, with each article being separated from the others. In addition to the disadvantage of the requirement of additional equipment, this type of equipment makes grouping of articles by parameters other than the number of articles per group difficult.
Such downstream equipment would further increase cost. Yet another disadvantage of such a system having separate pieces of equipment is that it is unlikely to be capable of rapid changeover to handle articles of different shapes and/or sizes.